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Dive into the research topics where Luuk Gras is active.

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Featured researches published by Luuk Gras.


AIDS | 2010

Life expectancy of recently diagnosed asymptomatic HIV-infected patients approaches that of uninfected individuals

Ard van Sighem; Luuk Gras; Peter Reiss; Kees Brinkman; Frank de Wolf

Objective:To compare life expectancies between recently diagnosed HIV-infected patients and age and sex-matched uninfected individuals from the general population. Design:National observational HIV cohort in the Netherlands. Methods:Four thousand, six hundred and twelve patients diagnosed with HIV between 1998 and 2007 and still antiretroviral therapy-naive as of 24 weeks after diagnosis were selected. Progression to death compared to the age and sex-matched general population was studied with a multivariate hazards model in 4174 (90.5%) patients without AIDS events at 24 weeks. Life expectancy and number of life years lost were calculated using the predicted survival distribution. Results:During 17 580 person-years of follow-up since 24 weeks after diagnosis [median follow-up 3.3 years, interquartile range (IQR) 1.6–5.8], 118 deaths occurred, yielding a mortality rate of 6.7 [95% confidence interval (CI) 5.5–8.0] per 1000 person-years. Median CD4 cell counts at 24 weeks were 480 cells/μl (IQR 360–650). According to the model, the median number of years lived from age 25 was 52.7 (IQR 44.2–59.3; general population 53.1) for men and 57.8 (49.2–63.7; 58.1) for women without CDC-B event. The number of life years lost varied between 0.4 if diagnosed with HIV at age 25 and 1.4 if diagnosed at age 55; for patients with a CDC-B event this range was 1.8–8.0 years. Conclusion:The life expectancy of asymptomatic HIV-infected patients who are still treatment-naive and have not experienced a CDC-B or C event at 24 weeks after diagnosis approaches that of non-infected individuals. However, follow-up time is short compared to the expected number of years lived.


AIDS | 2008

A resurgent HIV-1 epidemic among men who have sex with men in the era of potent antiretroviral therapy

Daniela Bezemer; Frank de Wolf; Maarten C. Boerlijst; Ard van Sighem; T. Déirdre Hollingsworth; Maria Prins; Ronald B. Geskus; Luuk Gras; Roel A. Coutinho; Christophe Fraser

Objective:Reducing viral load, highly active antiretroviral therapy has the potential to limit onwards transmission of HIV-1 and thus help contain epidemic spread. However, increases in risk behaviour and resurgent epidemics have been widely reported post-highly active antiretroviral therapy. The aim of this study was to quantify the impact that highly active antiretroviral therapy had on the epidemic. Design:We focus on the HIV-1 epidemic among men who have sex with men in the Netherlands, which has been well documented over the past 20 years within several long-standing national surveillance programs. Methods:We used a mathematical model including highly active antiretroviral therapy use and estimated the changes in risk behaviour and diagnosis rate needed to explain annual data on HIV and AIDS diagnoses. Results:We show that the reproduction number R(t), a measure of the state of the epidemic, declined early on from initial values above two and was maintained below one from 1985 to 2000. Since 1996, when highly active antiretroviral therapy became widely used, the risk behaviour rate has increased 66%, resulting in an increase of R(t) to 1.04 in the latest period 2000–2004 (95% confidence interval 0.98–1.09) near or just above the threshold for a self-sustaining epidemic. Hypothetical scenario analysis shows that the epidemiological benefits of highly active antiretroviral therapy and earlier diagnosis on incidence have been entirely offset by increases in the risk behaviour rate. Conclusion:We provide the first detailed quantitative analysis of the HIV epidemic in a well defined population and find a resurgent epidemic in the era of highly active antiretroviral therapy, most likely predominantly caused by increasing sexual risk behaviour.


Journal of Acquired Immune Deficiency Syndromes | 2007

CD4 cell counts of 800 cells/mm3 or greater after 7 years of highly active antiretroviral therapy are feasible in most patients starting with 350 cells/mm3 or greater

Luuk Gras; Anouk M. Kesselring; James Griffin; Ard van Sighem; Christophe Fraser; Azra C. Ghani; Frank Miedema; Peter Reiss; Joep M. A. Lange; Frank de Wolf

Objective:CD4 cell count changes in therapy-naive patients were investigated during 7 years of highly active antiretroviral therapy (HAART) in an observational cohort. Methods:Three endpoints were studied: (1) time to ≥800 CD4 cells/mm3 in 5299 therapy-naive patients starting HAART, (2) CD4 cell count changes during 7 years of uninterrupted HAART in a subset of 544 patients, and (3) reaching a plateau in CD4 cell restoration after 5 years of HAART in 366 virologically suppressed patients. Results:Among patients with <50, 50 to 200, 200 to 350, 350 to 500, and ≥500 CD4 cells/mm3 at baseline, respectively, 20%, 26%, 46%, 73%, and 87% reached ≥800 CD4 cells/mm3 within 7 years of starting HAART. Periods with HIV RNA levels >500 copies/mL and age ≥50 years were associated with lesser increases in CD4 cell counts between 6 months and 7 years. Having reached ≥800 CD4 cells/mm3 at 5 years, age ≥50 years, and ≥1 HIV RNA measurement >1000 copies/mL between 5 and 7 years were associated with a plateau in CD4 cell restoration. Conclusions:Restoration to CD4 cell counts ≥800 cells/mm3 is feasible within 7 years of HAART in most HIV-infected patients starting with ≥350 cells/mm3 and achieving sufficient suppression of viral replication. Particularly in patients ≥50 years of age, it may be beneficial to start earlier than current guidelines recommend.


Clinical Infectious Diseases | 2011

Immunodeficiency as a risk factor for non-AIDS-defining malignancies in HIV-1-infected patients receiving combination antiretroviral therapy.

Anouk M. Kesselring; Luuk Gras; Colette Smit; Gitte van Twillert; Annelies Verbon; Frank de Wolf; Peter Reiss; Ferdinand W. N. M. Wit

BACKGROUND The aim of this study was to investigate the association between immunodeficiency, viremia, and non-AIDS-defining malignancies (NADM). METHODS Patients starting combination antiretroviral therapy (cART) as of 1 January 1996 were selected from the AIDS Therapy Evaluation in the Netherlands (ATHENA) cohort. In Cox models, risk factors for NADM were investigated. These included age, sex, transmission route, smoking, alcohol abuse, prior AIDS diagnosis, duration of exposure to cART, and estimated duration of human immunodeficiency virus infection. CD4+ cell count and viral load (VL) were considered as time-updated variables and as measures of cumulative exposure to CD4+ cell counts of < 200, < 350, or < 500 cells/mm³ and detectable VL >50, >400, and >1000 copies/mL, respectively. RESULTS In a cohort of 11,459 patients, 236 NADMs were diagnosed; 102 were caused by infection, and 134 were attributable to other causes. Median CD4+ cell count at NADM diagnosis was 340 cells/mm³ (range, 210-540 cells/mm³). Median time to first NADM after starting cART was 5.0 years (range, 2.2-8.2 years). In multivariate models, cumulative exposure to CD4+ cell counts < 200 cells/mm³ remained significant (hazard ratio [HR], 1.12; range, 1.03-1.22) for each additional year of exposure. In stratified analyses, cumulative exposure to CD4+ cell counts < 200 cells/mm³ was associated with malignancies possibly caused by infection (HR, 1.16; range, 1.03-1.31]) but was not associated with other types of cancers. No significant effect of viremia was seen in either type of cancer. CONCLUSIONS Cumulative exposure to CD4+ cell counts < 200 cells/mm³ during cART was associated with an increased risk of infection-related non-AIDS-defining malignancies.


Lancet Infectious Diseases | 2016

Global epidemiology of drug resistance after failure of WHO recommended first-line regimens for adult HIV-1 infection: A multicentre retrospective cohort study

John Gregson; Michele Tang; Nicaise Ndembi; Raph L. Hamers; Soo-Yon Rhee; Vincent C. Marconi; Lameck Diero; Katherine A Brooks; Kristof Theys; Tobias F. Rinke de Wit; Monica Arruda; Frederico Garcia; Susana Monge; Huldrych F. Günthard; Christopher J. Hoffmann; Phyllis J. Kanki; N. Kumarasamy; Bernard Kerschberger; Orna Mor; Charlotte Charpentier; Eva Todesco; Casper Rokx; Luuk Gras; Elias K Helvas; Henry Sunpath; Domenico Di Carlo; Antonio Antinori; Massimo Andreoni; Alessandra Latini; Cristina Mussini

Summary Background Antiretroviral therapy (ART) is crucial for controlling HIV-1 infection through wide-scale treatment as prevention and pre-exposure prophylaxis (PrEP). Potent tenofovir disoproxil fumarate-containing regimens are increasingly used to treat and prevent HIV, although few data exist for frequency and risk factors of acquired drug resistance in regions hardest hit by the HIV pandemic. We aimed to do a global assessment of drug resistance after virological failure with first-line tenofovir-containing ART. Methods The TenoRes collaboration comprises adult HIV treatment cohorts and clinical trials of HIV drug resistance testing in Europe, Latin and North America, sub-Saharan Africa, and Asia. We extracted and harmonised data for patients undergoing genotypic resistance testing after virological failure with a first-line regimen containing tenofovir plus a cytosine analogue (lamivudine or emtricitabine) plus a non-nucleotide reverse-transcriptase inhibitor (NNRTI; efavirenz or nevirapine). We used an individual participant-level meta-analysis and multiple logistic regression to identify covariates associated with drug resistance. Our primary outcome was tenofovir resistance, defined as presence of K65R/N or K70E/G/Q mutations in the reverse transcriptase (RT) gene. Findings We included 1926 patients from 36 countries with treatment failure between 1998 and 2015. Prevalence of tenofovir resistance was highest in sub-Saharan Africa (370/654 [57%]). Pre-ART CD4 cell count was the covariate most strongly associated with the development of tenofovir resistance (odds ratio [OR] 1·50, 95% CI 1·27–1·77 for CD4 cell count <100 cells per μL). Use of lamivudine versus emtricitabine increased the risk of tenofovir resistance across regions (OR 1·48, 95% CI 1·20–1·82). Of 700 individuals with tenofovir resistance, 578 (83%) had cytosine analogue resistance (M184V/I mutation), 543 (78%) had major NNRTI resistance, and 457 (65%) had both. The mean plasma viral load at virological failure was similar in individuals with and without tenofovir resistance (145 700 copies per mL [SE 12 480] versus 133 900 copies per mL [SE 16 650; p=0·626]). Interpretation We recorded drug resistance in a high proportion of patients after virological failure on a tenofovir-containing first-line regimen across low-income and middle-income regions. Effective surveillance for transmission of drug resistance is crucial. Funding The Wellcome Trust.Summary Background Antiretroviral therapy (ART) is crucial for controlling HIV-1 infection through wide-scale treatment as prevention and pre-exposure prophylaxis (PrEP). Potent tenofovir disoproxil fumarate-containing regimens are increasingly used to treat and prevent HIV, although few data exist for frequency and risk factors of acquired drug resistance in regions hardest hit by the HIV pandemic. We aimed to do a global assessment of drug resistance after virological failure with first-line tenofovir-containing ART. Methods The TenoRes collaboration comprises adult HIV treatment cohorts and clinical trials of HIV drug resistance testing in Europe, Latin and North America, sub-Saharan Africa, and Asia. We extracted and harmonised data for patients undergoing genotypic resistance testing after virological failure with a first-line regimen containing tenofovir plus a cytosine analogue (lamivudine or emtricitabine) plus a non-nucleotide reverse-transcriptase inhibitor (NNRTI; efavirenz or nevirapine). We used an individual participant-level meta-analysis and multiple logistic regression to identify covariates associated with drug resistance. Our primary outcome was tenofovir resistance, defined as presence of K65R/N or K70E/G/Q mutations in the reverse transcriptase ( RT ) gene. Findings We included 1926 patients from 36 countries with treatment failure between 1998 and 2015. Prevalence of tenofovir resistance was highest in sub-Saharan Africa (370/654 [57%]). Pre-ART CD4 cell count was the covariate most strongly associated with the development of tenofovir resistance (odds ratio [OR] 1·50, 95% CI 1·27–1·77 for CD4 cell count Interpretation We recorded drug resistance in a high proportion of patients after virological failure on a tenofovir-containing first-line regimen across low-income and middle-income regions. Effective surveillance for transmission of drug resistance is crucial. Funding The Wellcome Trust.


AIDS | 2012

Is the virulence of HIV changing? A meta-analysis of trends in prognostic markers of HIV disease progression and transmission

Joshua T. Herbeck; Viktor Müller; Brandon Maust; Bruno Ledergerber; Carlo Torti; Simona Di Giambenedetto; Luuk Gras; Huldrych F. Günthard; Lisa P. Jacobson; James I. Mullins; Geoffrey S. Gottlieb

Objective:The potential for changing HIV-1 virulence has significant implications for the AIDS epidemic, including changing HIV transmission rates, rapidity of disease progression, and timing of ART. Published data to date have provided conflicting results. Design:We conducted a meta-analysis of changes in baseline CD4+ T-cell counts and set point plasma viral RNA load over time in order to establish whether summary trends are consistent with changing HIV-1 virulence. Methods:We searched PubMed for studies of trends in HIV-1 prognostic markers of disease progression and supplemented findings with publications referenced in epidemiological or virulence studies. We identified 12 studies of trends in baseline CD4+ T-cell counts (21 052 total individuals), and eight studies of trends in set point viral loads (10 785 total individuals), spanning the years 1984–2010. Using random-effects meta-analysis, we estimated summary effect sizes for trends in HIV-1 plasma viral loads and CD4+ T-cell counts. Results:Baseline CD4+ T-cell counts showed a summary trend of decreasing cell counts [effect = −4.93 cells/&mgr;l per year, 95% confidence interval (CI) −6.53 to −3.3]. Set point viral loads showed a summary trend of increasing plasma viral RNA loads (effect = 0.013 log10 copies/ml per year, 95% CI −0.001 to 0.03). The trend rates decelerated in recent years for both prognostic markers. Conclusion:Our results are consistent with increased virulence of HIV-1 over the course of the epidemic. Extrapolating over the 30 years since the first description of AIDS, this represents a CD4+ T cells loss of approximately 148 cells/&mgr;l and a gain of 0.39 log10 copies/ml of viral RNA measured during early infection. These effect sizes would predict increasing rates of disease progression, and need for ART as well as increasing transmission risk.


Journal of Acquired Immune Deficiency Syndromes | 2005

Mortality in patients with successful initial response to highly active antiretroviral therapy is still higher than in non-HIV-infected individuals.

Ard van Sighem; Sven A. Danner; Azra C. Ghani; Luuk Gras; Roy M. Anderson; Frank de Wolf

Mortality in HIV-infected patients has decreased dramatically since the introduction of highly active antiretroviral therapy (HAART). We analyzed progression to death in a population of 3678 antiretroviral treatment-naive patients from the ATHENA national observational cohort from 24 weeks after the start of HAART. Mortality was compared with that in the general population in the Netherlands matched by age and gender. Only log-transformed CD4 cell count (hazard ratio [HR] = 0.50, 95% confidence interval [CI]: 0.40 to 0.61 per unit increase) and plasma viral load (HR = 0.30, 95% CI: 0.15 to 0.60, HIV RNA level <100,000 vs. ≥100,000 copies/mL) measured at 24 weeks and infection via intravenous drug use (IDU) (HR = 0.16, 95% CI: 0.10 to 0.26, non-IDU vs. IDU) were significantly associated with progression to death. For non-IDU patients with 600 × 106 CD4 cells/L and an HIV RNA level <100,000 copies/mL at 24 weeks, mortality was predicted to be 5.3 (95% CI: 3.5 to 8.4) and 10.4 (95% CI: 6.4 to 17.4) times higher than in the general population for 25-year-old men and women, respectively, and 1.15 (95% CI: 1.08 to 1.25) and 1.29 (95% CI: 1.16 to 1.50) times higher for 65-year-old men and women, respectively. Hence, mortality in HIV-infected patients with a good initial response to HAART is still higher than in the general population.


AIDS | 2012

Long-term complications in patients with poor immunological recovery despite virological successful HAART in Dutch ATHENA cohort.

S.F. van Lelyveld; Luuk Gras; Anouk M. Kesselring; Shuangjie Zhang; F. de Wolf; A.M.J. Wensing; Andy I. M. Hoepelman; Annemarie E. Brouwer; P.P. Koopmans ; M. Keuter; A.J.A.M. van der Ven; H.J.M. ter Hofstede; R. de Groot

Objective:We investigated the risk of AIDS and serious non-AIDS-defining diseases (non-ADDs) according to the degree of immunological recovery after 2 years of virological successful antiretroviral therapy (HAART). Design:Retrospective observational cohort study including HIV-infected patients treated with HAART resulting in viral suppression (<500 copies/ml). Methods:Patients were grouped according to their CD4 cell count after 2 years of HAART: CD4 cell count less than 200 cells/&mgr;l (group A), 200–350 cells/&mgr;l (group B), 351–500 cells/&mgr;l (group C) or more than 500 cells/&mgr;l (group D). Analysis was done to assess predictors for poor immunological recovery and the occurrence of a composite endpoint [death, AIDS, malignancies, liver cirrhosis and cardiovascular events (CVEs)], non-ADDs, CVEs and non-AIDS-defining malignancies (non-ADMs). Results:Three thousand and sixty-eight patients were included. Older age, lower CD4 cell nadir and lower plasma HIV-RNA at the start of HAART were independent predictors for a poor immunological recovery. The composite endpoint, non-ADDs and CVE were observed most frequently in group A (overall log rank, P < 0.0001, P = 0.002 and P = 0.01). In adjusted analyses, age was a strong independent predictor for all endpoints. Compared with group A, patients in group D had a lower risk for the composite endpoint [hazard ratio 0.54 (95% confidence interval [CI] 0.33–0.87]; patients in group B had a lower risk for CVEs [hazard ratio 0.34 (95% CI 0.14–0.86)]. Conclusion:Poor immunological recovery despite virological successful HAART is associated with a higher risk for overall morbidity and mortality and CVEs in particular. This study underlines the importance of starting HAART at higher CD4 cell counts, particularly in older patients.


Clinical Infectious Diseases | 2008

Discontinuation of Nevirapine Because of Hypersensitivity Reactions in Patients with Prior Treatment Experience, Compared with Treatment-Naive Patients: The ATHENA Cohort Study

Ferdinand W. N. M. Wit; Anouk M. Kesselring; Luuk Gras; C. Richter; Marchina E. van der Ende; Kees Brinkman; Joep M. A. Lange; Frank de Wolf; Peter Reiss

BACKGROUND Recommendations that nevirapine (NVP) should be avoided in female individuals with CD4 cell counts >250 cells/microL and in male individuals with CD4 cell counts >400 cells/microL are based on findings in treatment-naive patients. It is unclear whether these guidelines also apply to treatment-experienced patients switching to NVP-based combination therapy. METHODS Patients in the ATHENA cohort study who had used NVP-based combination therapy were included. We identified patients who discontinued NVP-based combination therapy because of hypersensitivity reactions (HSRs; rash and/or hepatotoxicity) within 18 weeks after starting such therapy. We grouped patients according to their CD4 cell count at the start of NVP-based combination therapy (current CD4 cell count) as having a high CD4 cell count (for female patients, >250 cells/microL; for male patients, >400 cells/microL) or a low CD4 cell count. Treatment-experienced patients were further subdivided according to the last available CD4 cell count before first receipt of antiretroviral therapy (ART; pre-ART CD4 cell count) using the same criteria. Risk factors for HSR were assessed using multivariate logistic regression. RESULTS Of 3752 patients receiving NVP-based combination therapy, 231 patients (6.2%) discontinued NVP therapy because of HSRs. Independent risk factors included female sex and Asian ethnicity. Having an undetectable viral load (VL) at the start of NVP therapy was associated with reduced risk of developing an HSR (adjusted odds ratio [OR], 0.52; 95% confidence interval [CI], 0.38-0.71). Pretreated patients with low pre-ART and high current CD4 cell counts and a detectable VL when switching to NVP-based combination therapy had a significantly higher risk of developing an HSR, compared with treatment-naive patients who started NVP therapy with low CD4 cell counts (adjusted OR, 1.87; 95% CI, 1.11-3.12); pretreated patients with low pre-ART CD4 cell counts who switched to NVP therapy with a high current CD4 cell count and an undetectable VL did not have an increased risk of developing an HSR (adjusted OR, 1.03; 95% CI, 0.66-1.61). CONCLUSIONS Treatment-experienced patients who start NVP-based combination therapy with low pre-ART and high current CD4 cell counts and an undetectable VL have a similar likelihood for discontinuing NVP therapy because of HSRs, compared with treatment-naive patients with low CD4 cell counts. This suggests that NVP-based combination therapy may be safely initiated in such patients. However, in similar patients with a detectable VL, it is prudent to continue to adhere to current CD4 cell count thresholds.


AIDS | 2009

Clinical experience with the combined use of lopinavir/ritonavir and rifampicin

R.F.A. L'homme; Hanneke M. J. Nijland; Luuk Gras; Rob E. Aarnoutse; R. van Crevel; Martin J. Boeree; Kees Brinkman; Jan M. Prins; J.R. Juttmann; David M. Burger

Thirty-four patients treated concomitantly with lopinavir/ritonavir and rifampicin were evaluated. Overall, only 15% used the recommended increased dose of lopinavir/ritonavir. Of patients on a nonadjusted dose of lopinavir/ritonavir, 67% had a subtherapeutic lopinavir plasma concentration and 38% had a detectable viral load. Forty percent of patients on an increased dose of lopinavir/ritonavir prematurely stopped the drug combination because of adverse events. Combined use of lopinavir/ritonavir and rifampicin is challenging as it implies balancing between suboptimal efficacy and toxicity.

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Jan M. Prins

University of Amsterdam

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Peter Reiss

University of Amsterdam

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Colette Smit

University of Amsterdam

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F. de Wolf

University of Amsterdam

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